Shiftable block puzzle game



Sept. 1965 5, s o s 3,208,753

SHIFTABLE BLOCK PUZZLE GAME Filed Oct. '7, 1965 2 Sheets-Sheet 1 as INVENTOR. Sherley E. Sfofts I ZAMZ Z946 F|g.7 ATTORNEY Sept. 28, 1965 s. E. STOTTS 3,208,753

SHIFTABLE BLOCK PUZZLE GAME Filed Oct. '7, 1963 2 Sheets-Sheet 2 mul Sherley E. Sfofls j MK 0 mt,

ATTORNEY United States Patent 3,208,753 'SHIFTABLE BLOCK PUZZLE GAME Sherley E. Stotts, 2258 Cherry St, Denver, Colo. Filed Oct. 7, 1963, Ser. No. 314,107 3 Claims. (Cl. 273-132) This invention relates to games and puzzles and more particularly to game-puzzles of the type which involve a selected sequence of shifting movements of various members or blocks upon a board, as from an initial arrangement to a final arrangement. Accordingly, the invention will be hereinafter referred to as a block puzzle and also sometimes as a game-puzzle or as a game.

The primary object of the present invention is to pro vide a novel and improved block puzzle which includes a primary block and a plurality of smaller secondary blocks which are all placed upon a board in selected starting array with the play being to move the primary block from its starting position to a final posit on across the board by various and devious shifting movements of the other blocks to make Way for the primary block.

Another object of the invention is to provide a novel and improved block puzzle or game which is played by moving a primary block across a board by first moving s condary blocks in various and devious ways to make way for the primary block, and wherein the secondary blocks are of various sizes and shapes and are arranged in various groups, but with the size variations and groups arrangements being according to definite geometrical patterns at the commencement of the game.

Another object of the invention is to provide a novel and improved block puzzle of the type where groups of secondary blocks of various sizes and shapes are arranged about a larger primary block to commence the play of the puzzle according to a regular geometric pattern which may include a minimum number of secondary blocks sufficient to establish the pattern, or large numbers of the secondary blocks where it is desired to extend the pattern to increase the complexity of the puzzle.

A further object of the invention is to provide, in a novel and improved block puzzle or game which is played by moving a primary block across a board from an initial position to a final position, but where secondary blocks must be first shifted in various and devious ways to made way for the primary block, a further arrangement where by certain secondary blocks are also moved and shifted so that they will assume a selected final positioning about the primary block when the game is completed, or the puzzle solved.

Another object of the invention is to provide a novel and improved block puzzle or game wherein selected blocks are moved from an initial to a final position in a manner which permits the puzzle to assume the nature of a game of the type where certain blocks may symbolize members of significance and where maneuvers are involved as in an operation of surrounding a primary block with certain other blocks.

Another object of the invention is to provide in a block puzzle or game as above set forth, various symbols on selected blocks, as by placing fence sections on selected secondary blocks and a wild animal on a primary block to symbolize maneuvers involving surrounding the Wild animal within a pen or cage.

Yet another object of the invention is to provide a block puzzle or game using a primary block and geometrically interrelated groups of smaller secondary blocks which may be varied in number to permit the puzzle to be either a simple game with a minimum number of blocks which can be solved by anyone, or a complex game with a larger number of blocks and one which can be solved only by experts.

Other objects of the invention are to provide a novel ice and improved block puzzle or game which, though it may be complex in its actual maneuvers, it is easy to understand, easy to play, simple in construction, and may be produced as a low-cost, neat-appearing item.

With the foregoing and other objects in view, all of which more fully herein after appear, my invention comprises certain constructions, combinations, and arrangements of parts and elements as now described, defined in the appended claims, and illustrated in the accompanying drawing, in which:

FIGURE 1 is an isometric View of a first, simplified form of my block puzzle using 8 blocks on the board with the blocks being positioned to commence a play.

FIGURE 2 is a transverse sectional View as taken from the indicated line 2-2 at FIG. 1 to illustrate the basic construction of the components forming the puzzle.

FIGURE 3 is an isometric view of a second, more complex, form of my block puzzle using 15 blocks on the board and with the blocks being positioned to commence solving the puzzle.

FIGURE 4 is an isometric view of a third, yet more complex form of the block puzzle using 24 blocks on the board and with the blocks being positioned to commence solving the puzzle.

FIGURE 5 is an isometric view of the block puzzle illustrated at FIG. 3, but showing the blocks as they will be positioned at one stage during the course of solving the puzzle.

FIGURE 6 is an isometric view of the block puzzle illustrated at FIG. 3, but showing the blocks as they will be positioned when the puzzle is solved.

FIGURE 7 is a fragmentary plan view of a portion of the puzzle illustrated at FIGS. 3, 5, and 6, showing the blocks as they will be positioned at one stage when solving the puzzle and illustrating specifically a setup necessary when one of the blocks is to be rotated as in the manner indicated by an arrow.

Referring more particularly to FIG. 1 of the drawing, the more simple puzzle therein depicted is illustrative of the general structure and arrangement of any of the other more complex puzzles which may be formed according to the invention. The puzzle consists of fiat, square or rectangular blocks generally indicated as 10, mounted upon a flat board 11. The geometrical interrelationship between the blocks at the beginning of a game is in the form of progressive arrangements of groups of blocks as squares as will be hereinafter explained.

Accordingly, the board 11 is in the form of a square and it consists of a flat base member 12 and walls 13.at each edge thereof so that the board 11 is in the general form of a shallow pan-like enclosure to contain the blocks 10 therein. The blocks, the base member, and the Walls thereof will be formed of rigid, smooth sheet materials such as certain types of synthetic resins or of a good grade of plywood, and the materials will be smoothly finished with comparatively close clearances so as to permit smooth, easy sliding of the blocks within the board Without improper rotation of any blocks because of loose fitting of the blocks within the board. To complete the board 11, portions of the walls 13 are raised adjacent to one corner to extend above the blocks and form a symbolic fence 14 which will be hereinafter further described.

The preferred mode of solving the puzzle is to convert it into a game symbolizing the pinning or fencing in of a wild animal and the puzzle will be hereinafter described as such a game. Accordingly, the primary block 15 which is to be moved across the board will include a statuette 16, or picture or symbol indicating the wild animal. The pen within which the animal will be confined will be formed by the fence portions 14 at one corner of the board and by other fence portions 17 on other blocks as will be later described.

The blocks are positioned at the commencement of the game according to a geometric pattern and the corner 18 of the board 11 which is diagonally opposite to the corner Where the fence 14 is located, is referred to as the beginning point or point of origin when describing the board 11 in a geometrical manner. Extending from this origin corner 18 to the right is what will be called a right-left wall 13x and perpendicular thereto is what will be called an up-down wall 13y, and this manner of reference will be used to indicate the direction of movement of the several blocks on the board either to the right, or left, or up or down. For example, the primary block 15 will be initially set at the origin position which may be called the lower-left corner of the board, and it will ultimately be moved to the corner which may be called the upper-right corner which is within the confines of the fence 14.

The blocks are adapted to be mounted upon the base 11 in a selected geometric array at the commencement of the game to solve the puzzle. The square primary block is located at the origin corner 18. Other blocks surround this primary corner block in arrays of squares, and all of the blocks and the board 11 are proportioned to some multiple of a unit or module of length. In the puzzle illustrated in FIG. 1, this module is six units along each side.

The primary block 15 is the largest of the group, and the length of each side is three units. A first group of three blocks 10 surrounds the primary block, and this group and the primary block form a square five units in length (in the illustration at FIG. 1 one of these blocks is removed). A second group of five blocks surrounds the first group and the aggregate of nine blocks make up a square six units in length to complete the blocks in this puzzle. Each block in this puzzle is individually identified and marked in left-to-right rows commencing with the primary block 15 which is marked A. Block B (not shown at FIG. 1) and block C complete the first row, blocks D, E, and F form the second row and blocks G, H, and I complete the third row.

The first said group surrounding the primary block A consists of two rectangular blocks B (not shown) and D which are three units long and two units wide and a square corner block E which is two units square. The second said group surrounding the first consists of two rectangular blocks C and G which are three units long and one unit wide, two rectangular blocks F and H which are two units long and one unit wide and a square block I which is one unit square.

The more complex game puzzles illustrated at FIGS. 3 and 4 are of substantially identical construction, incorporating, however, a larger number of blocks, the puzzle illustrated at FIG. 3x including a third group of seven blocks surrounding a first group of three and a second group of five in the form of a square and the puzzle illustrated at FIG. 4 including a fourth group of nine blocks surrounding a first group of three, a second group of five and a third group of seven blocks.

Referring more particularly to the puzzle at FIG. 3, the puzzle is formed by blocks 10a, which are mounted upon a board 11a formed by a base 12a and walls 13a. The fence sections 14a on the walls, the primary block 15a, the animal 16a on the block, the fence portions 17a on selected individual blocks and the origin corner 18a of the board are substantially of the same construction as that hereinbefore described except for size. The module length of the board is ten units along each side and the size of the primary block 15a is four units square. The first group of three blocks surrounding the primary block with the primary block forms a square seven units in length. The second group of five blocks surrounding the first, with the primary block and the first group, forms a square nine units in length and the third group of seven blocks surrounding the second, with the other blocks, forms the square of ten units in length to complete the arrangement. Each block in this puzzle is individually identified and marked in left-to-right rows commencing with the primary block 15a which is marked Aa. Block Ba (not shown) and blocks Ca and Da complete the first row. Blocks Ea, Fa, Ga, and Ha complete the second row. Blocks Ia, Ia, Ka, and La complete the third row. Blocks Ma, Na, 0a, and Pa complete the fourth row.

The first said group surrounding the primary block Aa consists of two rectangular blocks Ba (not shown) and Ea which are four units long and three units wide and a square corner block Fa which is three units square. The second group surrounding the first consists of two rectangular blocks Ca and Ia which are four units long and two units wide, two rectangular blocks Ia and Ga which are three units long and two units wide and a square corner block Ka which is two units square. The third group surrounding the sec-0nd consists of .two rectangular blocks Da and Ma which are four units long and one unit wide, two rectangular blocks Ha and Na which are three units long and one unit wide, two rectangular blocks La and 0a which are two units long and one unit wide and one square block Pa which is one unit square.

Referring more particularly to the puzzle at FIG. 4, the puzzle is formed by blocks 10b which are mounted upon a board 11b formed by a base 12b and walls 13b. The fence sections 14b, the primary block 15b, the animal 16b, the fence portions 17b on selected blocks and the origin corner 18b of the board are substantially of the same construction as that hereinbefore described, except for size. The module length of the board is fifteen units along each side and the size of the primary block 15b is five units square. The first group of three blocks surrounding the primary block, with the primary block, forms a square nine units in length. The second group of five blocks surrounding .the first, with the primary and first group forms a square twelve units in length. The third group of seven blocks, with the primary block and the first and second groups, forms a square fourteen units in length and the fourth group of nine blocks, with the primary block and the first, second, and third groups, forms .the square of fifteen units in length to complete the arrangement. Each block is individually identified and marked in left-to-right rows commencing with the primary block 15b which is marked Ab. Block Bb (not shown) and blocks Cb, Db, and Eb complete the first row. Blocks Pb, Gb, Hb, Ib, and J b complete the second row. Blocks Kb, Lb, Mb, Nb, and Ob complete the third row. Blocks Pb, Qb, Rb, Sb, and Tb complete the fourth row, and blocks Ub, Vb, Wb, Xb, and Yb complete the fifth row.

The first said group surrounding the primary block Ab consists of two rectangular blocks Bb (not shown) and Pb which are five units long and four units wide and a square corner block Gb which is four units square. The second said group surrounding the first consists of two rectangular blocks Cb and Kb which are five units long and three units wide, two rectangular blocks Hb and Lb which are four units long and three uni-ts wide and a square corner block Mb which is three units square. The third group surrounding the second consists of two rectangular blocks Db and Pb which are five units long and two units wide, two rectangular blocks Ib and Qb which are four units long and two units wide, two rectangular blocks Nb and Rb which are three units long and two units wide and a square corner block Sb which is two units square. The fourth said group consists of two rectangular blocks Eb and Ub which are five units long and one unit wide, two rectangular blocks lb and Vb which are four units long and one unit wide, two rectangular blocks Ob and Wb which are three units long and one unit wide, two rectangular blocks Tb and Xb which are two units long and one unit wide and a square corner block Yb which is one unit square.

It is immediately manifest that more elaborate and larger groups of blocks can be formed according to simple rules of arithmetic and geometric progression.

The module or unit of size is established by the smallest square block in the upper right corner of the board such as block Yb at FIG. 4. Proceeding diagonally across the board towards the primary block 15b, the blocks Sb, Mb, Gb, and Ab (15b) progressively increase one unit in size from the unit square Yb, .to the two unit square Sb, to the three unit square Mb, to the four unit square Gb, and .to five unit primary block Ab. The next larger puzzle would have a primary block of six units square and would require thirty-six blocks. A yet larger puzzle would have a primary block of seven units square and would require forty-nine blocks.

One play of a game for each of the puzzles described consists in moving the primary block, 15 or 15a or 15b, from the origin point 18 at the lower left corner to the corner at the upper right where the respective fence portions, 14 or 14a or 14b, will surround two sides of the primary block. The respective fence portions, 17 or 17a or 17b, on other selected blocks will also be moved about the primary block so that it will be completely surrounded by a fence and the animal 16, or 16a or 16b, on the block will be symbolically fenced in. Various phases of the play of the intermediate puzzle illustrated at FIG. 3 are set forth at FIGS. 5, 6, and 7. FIG. 5 shows the blocks at an intermediate position during the course of play. FIG. 6 shows the blocks at their final position with the primary block 15a being within the fenced section 14a and with other fence portions 17a enclosing the primary block. It is to be noted that the sections making up the fence portion 17a are at the upper end of block Da at the right side of block Fa at the upper end of block Ia and at the upper end of block Na. FIG. 7 illustrates the manner and conditions which must exist when a block is to be rotated as is sometimes necessary in the game.

The solution of this game illustrated at FIGS. 5, 6, and 7 will now be set forth in detail by referring to movements of the blocks as being up and down and left and right as herein-before defined. The block Ba is removed at the beginning of the game as illustrated to provide a space wherein other blocks may be moved, and the entire play must be restricted to movement within a space of this area occupied by block Ba. The individual block movements are as follows, and the notation infers that the movements will be as far as possible in the direction indicated: Ca and Da left. Ha down and left. Ga to the right. Ha up and between Ga and Fa. Ca and Da right. Fa down. Ha left, turning counterclockwise,

down and against Fa.

At this point the blocks are positioned as in the manner illustrated at FIG. 7 which illustrates the space which must be provided for rotating a block, where the length and width of the space must be greater than the diagonal dimension of the block so that it may rotate without jamming. The moves continue as follows: Ia down, turning clockwise. Ka left. La left and down alongside Ja. Pa down and left and upon La. Pa and La left and against Ia. Oa down, turning counterclockwise between La and Ga. Ka right and up to top of board. 0:: up, turning counterclockwise and right between Ga and Ka. Pa and La right adjacent to Ga. Na right, turning counterclockwise and down between Pa and La and Ja. Ma right and down on Ja, Na, and Pa. Ia up. Ma left between Ia and Ba. Ia, Na, Pa, and La up as a group. Ea right. Ia and Ma down. Ia, Na, Pa, and La left to upper left corner of board. 0a and Ka left. Ga up, Ea, Ia, Ma, right. Ia down. Na, Pa, and La left. Ka and 00 right. Ma and Ia up. Ea left. Ga down. Oa, Ka, Ma, and Ia right. Ea right. Pa and La right and down. Na right to turn clockwise and to upper left hand corner of board. Pa and La up. Turn Ia counterclockwise and up alongside Na. Aa up. Fa left.

At this point the blocks are positioned as in the manner illustrated at FIG. 5. The moves continue as follows: Ha down, turn counterclockwise and left against Fa.

6 Ca and Da left. Ga and 0a down. Ba and Ma right. Ca up. Da left. Ga left, turns counterclockwise, down and right to lower right hand corner of the board. Oa left, turns counterclockwise and right. Da right. Ca down. Ba and Ma left. Oa left. Ka down. Ea, Ma, and Ia right. Ca up. Da left and up. Oa left and up between Da and Ea. Ka left and down. Da, Oa, Ea, Ma, Ia, and Ca down. Pa right and down. La up, turns clockwise, right and down upon Ia. Na right. Ia up and right. Aa up and to left hand corner of board. Fa up. Ha turns clockwise left and up against Fa. Da left and up. Ka left. Oa down and left. Ga left. Ea, Ma, Ia,

Pa, La, Na, and Ca down. Ja right. Aa right. Ha and Fa up. 0a and Ka up. Ga left, Ca and Da, 0a and Ka down. Ia left. Na, Pa, and La down and left. Ia down. Ha, Fa, and An to the right as a group and this move completes the game with the primary piece Aa being at the upper right corner of the board and surrounded by the fence 14a on the board walls 13a and the fence sections 17a on the blocks Fa, Ha, Ia, and Na, as in the manner clearly illustrated at FIG. 6.

The solution to the game illustrated at FIG. 1 is more simple. It is to be noted that fence sections are on the blocks D, F, and G. To begin the game, the block B is removed as illustrated, and the block C is lifted from its position and rotated degrees, this being necessary since the small number of blocks do not otherwise permit space for rotation of this member. Thence, the individual block movements are as follows: C, E, F, H, and I down. G right. D up. H and I left. G down. D left. A, H, and I up. C left and up. D, G, E, and F down. H and I right. C and A up. E and F left. G down. C right and down. E and F up. G left. C and D down. H down, turns counterclockwise and right between D and I. A right. E up. F left, turns clockwise and up. D left. H down, turns clockwise and up and left to be underneath A. I down. A right to upper right hand corner. C and I up. G right. D down. F turns counterclockwise and up between E and A. D up. C left and down. H and I down and left. G up, and this move completes the game as the primary piece A at the upper right hand corner of the board is surrounded by the fence portions 14 on the walls 13 and the fence portions 17 on the blocks D, F, and G. It is to be noted that this game could be shortened if the fence portions were placed on the blocks I, H, F, and E, and a corner of a fence portion on block D since these blocks first surround A when it first reaches the upper right hand corner.

The solution to the game illustrated at FIG. 4 is more complex, but this solution demonstrates that solutions will exist with other even more complex games constructed according to the invention. With the block Bb removed to initiate the game, the moves are as follows: Cb, Db, and Eb left. Jb down and left. Ib down. Hb right. I b up and left. Hb left. Ib up and alongside Hb. Cb, Db, and Eb right. Gb down. Ib left, turn and down upon Gb. Hb and lb left. Ob down, turn and left. Tb down, turn and right. Mb and Nb right and down. Rb and Sb right and down. Wb down, turn and left alongside Lb. Xb left, turn and down alongside Qb. Vb right. Hb, Ib, Wb, Lb, Xb, and Qb up. Ob and Tb left. Rb, Sb, Mb, and Nb down. Yb down. Turn Vb counterclockwise and right above Yb. Mb and Rb up. Nb and Sb left. Vb and Yb down. Mb and Rb right. Nb and Sb up. Yb left. Vb turns clockwise, right and down. Hb and lb right. Ob and Tb up. Fb right. Ab up. Gb left. Jb down, turns and to left. Cb and Db left.

Next a more complicated move. Yb moves partially down. Vb moves left and rotates approximately 45 degrees. Pull bottom of Eb to the left until it is almost lying down. Then pull Hb and Ib down far enough to allow Ob and Tb to move to the right. Then Fb, Cb, and Db up. Now Eb may be fully turned to lay down at the bottom of the board and be moved left. Vb turned back and down and left against bottom of board and against Eb. Yb tolower right hand corner.

: Ob, Tb, Hb, and lb down. Fb right. Qb, Xb, Wb, and Lb down. Pb right and up. Qb, Xb, Lb, Wb, Cb, Db up. Kb, Ab, Gb, and lb up. Eb left. Vb and Yb left, up and left. Hb and Ib down. Cb and Db down. Ob and Tb left. Fb, Mb, Nb, Rb, and Sb down. Pb right. Qb, Xb, Lb, and Wb down. Ub right and down. Kb up. Ub left. Qb, Xb, Lb, Wb, Ob, Tb, Cb, and Db up. Hb and Ib left. Fb, Mb, Nb, Rb, and Sb down. Ob and Tb right and up. Lb and .Wb down and right. Qb and Xb down. Ub and Kb right. Ab, Gb, J b, Vb, Yb and Eb up. Hb and Ib left. Cb and Db down. Rb and Sb left and down. Oh and Xb down and right. Ub and Kb down. Pb left and down. Ob and Tb up, left and down. Lb, Wb, Qb, Xb, Mb, and Nb up. Rb and Sb right. Ub, Kb, Pb, Tb, and Ob down. Lb and Wb left. Qb, Xb, Mb, Nb, Rb, and Sb up. Ub right and down. Kb down and right. Lb, Wb, Ob, Pb, and Tb down. Qb and Xb left. Kb, Rb, Sb, Mb, and Nb up.

Pb right. Lb and Wb up. Ob turns, up and left. Tb turns, down and left. Xb and Wb down and left. Pb and Kb left. Mb and Rb down. Nb and Sb right. Ab,

Qb, and Lb right.

6b and Vb up. Jb, Yb, Ob, Tb, Xb, Wb, Kb, Pb, Mb, and Rb left. Nb and Sb down and left. Lb, Qb, Ab, Gb, and Vb right. I b, Yb, Ob, and Tb up. Xb, Wb, Kb, Pb, Mb, Rb, Nb, and Sb left. Qb and Lb down. Vb, Gb, and Ab then move to the right, and this move completes the game. The primary block Ab is at the upper right hand corner where the fence sections 14b are located and the other fence sections 17b on the adjacent blocks Gb, Vb, Nb, and Qb complete the enclosure.

I have now described my invention in considerable detail. game and puzzle art can build and devise alternate and equivalent constructions which are nevertheless within the spirit and scope of my invention. Hence, I desire that my protection be limited, not by the constructions illustrated and described, but only by the proper scope of the appended claims.

I claim:

1. A game puzzle of the type played by shifting blocks upon a board from a selected starting arrangement to a selected finish arrangement and comprising:

(a) a square board having walls thereabout to form a a square enclosed field within the confines of the walls;

-(b) a plurality of rectangular and square blocks adapted to be placed upon the field in a mosaic-like pattern and in regular rows and columns when in said starting arrangement, each block and the square field being proportioned according to a common module of length;

(c) a square block at one corner of the field having a length of one module on each side with the row and column of blocks aligned with this block having a width of one module at one side of each block;

(d) a second square block within the field arranged in However, it is obvious that others skilled in the a diagonal pattern with respect to the first and with one corner thereof touching a corner of the first and having a length of two modules with the row and column of blocks aligned with this block having a width of two modules at one side of each block;

(e) a further sequence of square blocks within the field arranged in a diagonal pattern with the corner of one block touching the corner of the next adjacent block, in tandem, with the size of each successive square increasing in size one module and with the column and row of blocks aligned with each square having comparable width at one side of each block; (f) a final squareblock of maximum size at the corner of the field diagonally opposite the first, and with the column adjacent said final block being deficient of blocks to provide an open portion of the field; and,

(g) symbols on selected blocks adapted to be arranged in a correlated manner when the blocks are moved to the finish position.

2. A game puzzle of the type which is played by shifting a group of blocks upon a board from a selected starting arrangement to a selected finished arrangement, and comprising:

(a) a square board having peripheral walls forming an enclosed field within the confines of the walls;

(b) a plurality of rectangular blocks interrelated in size to the size of the field by a common module of length, adapted to be placed upon the field in a mosaic-like pattern in a selected starting arrangement with the blocks partially covering the surface of the field and with the unco-veredsurface of the field being sufiicient to permit limited movement of the blocks, wherein the sizes of the blocks vary according to a regular progressive change of modular dimension, wherein the largest and smallest blocks are formed as squares, the smallest having a length of one module at one side and the largest block having a length of a selected multiple of the module at each side, wherein the other blocks on the board are formed as rectangular and square members of uniformly lateral and transverse proportions to form a regular arrangement having sides and ends of selected multiples of said module at each side, and, wherein the number of blocks on the board is one less than the square of the modular length of the largest member; and,

(c) symbols on selected blocks adapted to be arranged in a selected manner when the blocks are moved to a finished arrangement.

3. In the puzzle defined in claim 1, wherein the total number of blocks is one less than the square of the modular length of the largest member.

References Cited by the Examiner UNITED STATES PATENTS DELBERT B. LOWE, Primary Examiner. 

2. A GAME PUZZLE OF THE TYPE WHICH IS PLAYED BY SHIFTING A GROUP OF BLOCKS UPON A BOARD FROM A SELECTED STARTING ARRANGEMENT TO A SELECTED FINISHED ARRANGEMENT, AND COMPRISING: (A) A SQUARE BOARD HAVING PERIPHERAL WALLS FORMING AN ENCLOSED FIELD WITHIN THE CONFINES OF THE WALLS; (B) A PLURALITY OF RECTANGULAR BLOCKS INTERRELATED IN SIZE TO THE SIZE OF THE FIELD BY A COMMON MODULE OF LENGTH, ADAPTED TO BE PLACED UPON THE FIELD IN A MOSAIC-LIKE PATTERN IN A SELECTED STARTING ARRANGEMENT WITH THE BLOCKS PARTIALLY COVERING THE SURFACE OF THE FIELD AND WITH THE UNCOVERED SURFACE OF THE FIELD BEING SUFFICIENT TO PERMIT LIMITED MOVEMENT OF THE BLOCKS, WHEREIN THE SIZES OF THE BLOCKS VARY ACCORDING TO A REGULAR PROGRESSIVE CHANGE OF MODULAR DIMENSION, WHEREIN THE LARGEST AND SMALLEST BLOCKS 